Tools / File Converter / MP4 to AU Converter

MP4 to AU Converter

Convert MP4 files to AU. Free, without uploading.

This tool converts MP4 files to AU. MP4 is the most widely used video format. It usually holds H.264 video and AAC audio and plays on phones, browsers, TVs and social networks.

Sun/NeXT audio. Only the audio of the MP4 video is kept and saved as AU; the picture is dropped. AU is lossless, so the audio keeps the quality it has in the MP4 file.

Conversion runs on your device; your file is never sent to a server. The components download once on first use, and later conversions start right away.

How to use

1. Choose the MP4 video, drag it in, or paste its link.
2. Choose the audio quality; optionally enter a start and end time.
3. Press "Convert" and download the AU file.

Frequently asked questions

Will audio quality drop when converting to AU?

No. AU is lossless.

Is there a file size limit?

No fixed limit; your device’s memory decides. Computers usually handle files up to 1–2 GB.

Is my file uploaded?

No. Your MP4 file is converted to AU inside your browser.